There are many types of electronic instruments, all of them being relatively expensive, such as marine sonar devices, global positioning devices (GPS), among others, that are designed with threaded holes in opposed sides of the body of the instrument. Normally, these instruments are installed between a U-shaped bracket having circular openings or slots aligned with threaded holes of the instrument. A pair of screws or threaded rods or even handles having threaded ends are used to secure the sonar unit, or GPS, to the bracket. This mounting system allows the instrument to be pivoted to any desired angle for viewing. The addition of slots to the bracket also permits some vertical adjustability in addition to this angular adjustability. Obviously, by tightening the screws, or threaded rods, one can secure both the vertical position of the device and its angle of tilt. In this inventor's experience, boaters prefer electronic instruments such as sonar to be raised off the console so they are more readily visible from a standing position, such as when the driver of the boat is standing at the wheel for better visibility.
Frequently, a ball mount stand is used so that the instrument can be raised and lowered and adjusted infinitely between a fully raised or lowered position. The ball mount stand uses clamping pressure applied by a threaded rod having a handle on it. The stand itself is nothing more than a clamshell design. One end of the clamshell is placed over a ball that is permanently affixed to a surface, such as a console. The other end of the clamshell is placed over a ball that is mounted to the underside of the instrument. The threaded rod is then inserted through threaded apertures in the clamshell design and tightened to the point that the stand maintains its position over the console.
Unfortunately, as easily and conveniently as the aforementioned mounting devices are to install, it is equally as easily to remove them. The valuable nature of GPS units and marine sonar units also makes them an easy potential target for thieves.